Art of rolling tubes.



PATENTED FEB. 24, 1903.

' M. MANNESMANN.

ART OF ROLLING TUBES. 1 APPLICATION FILED 0013, 1901. RENEWED SEPT. 17.1902. no MODEL. a aann'rs-snm 1.

"a a- I Qummtoz PATENTED FEB. 24, 1903.

-M..-:--MAN -N-EsMAN-N.

ART OF ROLLING TUBES. APPLICATION I ILBD OUT. 3, 1901. RENEWED SEPT. 17,1902.

3 SHEETS-SHEET 2.

F0 MODEL.

\1 Q .a 1 v 2 y 3 mm wbo z No. 721,210. PATENTBD FEB.24,1 903.

la 7 976317% v UNITE STATES P TENT OFFICE.

MAX MANNESMANN, OF REMSCHEID=BLIEDINGHAUSEN, GERMANY.

ART OF ROLLING TUBES.

SPECIFICATION forming part of Letters Patent N 0. 721,210, datedFebruary 24, 1903.

Application filed October 3, 1901. Renewed'Septem'ber 17, 1902. SerialNo. 124,808. (No model.)

pending application, Serial No. 77,926, filed October 7, 1901, in whicha hollow billet or blank is rolled out into a tube betweenpositively-driven rolls and a stationary or loose mandrel, the rollscompressing the blank on .the mandrel and squeezing some of thema terialof the blank between their edges, so as to form longitudinal ribs,ridges, feathers, of fins on the tube.

My improvement has for its object to use instead of a loose orstationary mandrel a positively endwise actuated mandrel which is drawnthrough the rolls by a draw-bench.

In application Serial No. 68,988 ,only the friction of the rolls on theblank furnishes the power to draw in and roll out the blank; but in thepresent application the friction of the rolls on the blank is aided bythe friction of the positively endwise moved mandrel on the innersurface of the blank, whereby a greater'reduction of the blank betweenthe rolls can be obtained.

This invention is an improved art of rolling tubes from a hollow blankor billet, in which (a) the simultaneous action of positively-drivenrolls and (b) a positively-actuated mandrel (drawn in longitudinaldirection through the rolls) and (c) a proper calibrating of the rollsare simultaneously made use of for rolling the blank or billet into atube; and the invention consists of the art of rolling tubes bysubjecting the hollow blank or billet, which is considerably larger thanthe roll-groove, to the simultaneous action of positively-driven rollsand a longitudinallydrawn mandrel in connection with properlycalibratedrolls, the edges of which first impinge upon the blank before the mainbodies of the rolls take hold of the same-and then squeeze sidewise acertain quantity of material at the spaces between the edges of therolls, so as to form exterior longitudinal ribs, fins, or ridges alongthe tube thus formed.

one pass.

Only by the simultaneous combination of the three effects statednamely,the action of positively-driven rolls, the longitudinal motion of amandrel drawn positively through the rolls, and the proper calibratingof the rolls, so that the edges of the grooves of the same impinge firston the blankcan the blank or billet be stretched out sufficiently toproduce a finished tube in one heat and If the proper calibrating of therolls and the consequent squeezing action of the edges of the rolls onparts of the blank or billet were omitted and the blank or billet merelytreated in the well-known manner between positivelydriven'rolls withoval caliber, it would be impossible to complete the tube in one pass,even if the positively-driven rolls and the longitudinally-actuatedmandrel were simultaneously employed, for the simple reason that thetube would assume betweenthe rolls an oval shape and would be compelledto be turned for an angle of ninety degrees and be then again passedthrough a second set of rolls of smaller caliber, then again be turnedfor an angle of ninety degrees and again passed through a set of rollsof still smaller caliber, and so on until the required length andthickness of the tube are obtained.

In the accompanying drawings, Figure 1 represents a side elevation of atwo-roll rolling-mill, illustrating my improved process of rollingtubes. Fig. 2 is a plan view of Fig. 1, in which the upper roll is takenofi in order to show the blank in the process of being rolled out. Fig.3 is a vertical transverse section of the tube on line 3 3, Figs. 1 and2, without the rolls and mandrel. Figs. 4 and 5 are a side elevation andplan view of a drawbench for imparting a draw motion to the mandrel.Fig. 6 is a diagram of the rolls, mandrel, andblank. Figs. 7 to 12 arevertical transverse sections, respectively, on lines 7 7, 8 8, 9 9, l010, 1111, 12 12 in Fig. 6, showing the progress of the blank through therolls and the changes imparted thereto by the squeezing edges and rimsof the rolls. Fig. 13 is an end view of a rolling-mill with three rolls,the mandrel and the rolled-out tube being in cross-section. Fig. 14; isa cross-section through the mandrel and tube shortly after the firstpoints of contact at the entry of the roll-pass. The adjacent surfacesof the three rolls are marked by section.

Similar letters of reference indicate corresponding parts.

Referring to the drawings, a a and g g g are the rolls, b a hollow blankor billet, and m a mandrel on which the blank is placed. To the rolls aa, and g g g positive motion is imparted in the direction shown byarrows in Figs. 1 and 13, while simultaneously with the motion of therolls a longitudinal motion is imparted to the mandrel m by a suit-abledraw-bench or other equivalent mechanism (Z and shown in Figs. 4 and 5.The caliber of the rolls is such that at both sides of the groovedworking faces circumferential rims a and g are formed. The edges betweenthe grooves and the rims first impinge upon the blank, whereby thehollow blank or billet is squeezed at the sides and rolled out into atube in one pass.

In Fig. 2 the upper roll is removed in order to clearly show the actionof the rolls on the blank.

Fig. 3 shows a cross-section of the to be along the line 3 3, Figs. 1and 2, illustrating the rolling out of the longitudinal ribs or feathersr alongside of the tube, said ribs or feathers being produced by thesqueezing of the material in the spaces between the ribs of the rolls.These ribs or feathers r can be readily removed, if necessary, from thefinished tube by cutting them off, or they may remain thereon, asdesired.

Fig. 14 is a cross-section through the mandrel and the blank shortlyafter the points of first impingement of the rolls on the hollow blank.The rolls touch the blank only at their edges g the part of the caliberadjacent to the blank at this point being marked by section. While theedges 9 of the rolls impinge upon the hollow blank and compress it onthe mandrel, the grooved center portions of the rolls 9 do not yet touchthe blank. Fig. 13 shows the feathers 7" between the circumferentialrims g g of the rolls 9.

The caliber of the rolls is nearly a circle in cross-section. The edgesmay be sharp or rounded off.

In carrying out my improved process of rolling tubes a hollow blank orbillet the exterior diameter of which is considerably larger than thegroove of the rolls is subjected to the action of positively-drivenrolls and the action of a longitudinally-drawn mandrel andsimultaneously to the squeezing action of the edges of the rolls, whichimpinge first on the sides of the blank, produce a gradual squeezing orcrowding of the material in lateral direction and the formation oflongitudinal ribs or feathers between the edges or the rims of therolls. The grooves with their sharp or rounded-off edges are the mostimportant working parts of the rolls, which act on the blank togetherwith the drawn mandrel and which may be aided by parallel orother rimsoutside of the edges and grooves. In the latter case the rims compressand roll out the fins, feathers, or ribs squeezed down or produced bythe edges. The rolls in such case impinge on the blank not only at theirgrooved portion or caliber, but, besides, at the rims, so as to rolldown the ribs or feathers and take powerful hold of the same. Thedrawing forward of the tube and ribs causes the material of the blankunder the compression action of the rolls to be drawn out and stretched.

Instead of two rolls, as shown in Figs. 1 to 12, three or more rolls maybe employed, as shown in Figs. 13 and 14, which are still more capableof strongly reducing the cross-section of a blank or billet in one passwithout producing inside folds on the rolled-out tube than two rolls.

By the above-described process, and especially with the use of three orfour rolls forming a caliber, a relatively large reduction can beperformed in one pass. The reduction may even be so much increased thatthe tube or blank after one pass through the rollingmill has twice,three times, or more the length of the hollow blank before the pass.

Having thus described my invention, I claim as new and desire to secureby Letters Patent- 1. The art of rolling a hollow blank or billetbetween two or more rolls and a mandrel which consists in subjecting theblank to the action of positively-driven rolls and alongitudinally-actuated mandrel simultaneously with the squeezing actionof the edgesof the rolls, whereby a relatively large reduction of theblank and a stretching of the same in a longitudinal direction into atube with longitudinal ribs or feathers is produced, substantially asset forth.

2. The art of rolling a hollow blank or billet between two or more rollsand a mandrel, which consists in subjecting the blank to the action ofpositively-driven rolls and a longitudinally-actuated mandrel,simultaneously with the squeezing action of the edges of the rolls whichimpinge upon the blank before the main body of the caliber takes hold ofthe blank, whereby a stretching of the blank in longitudinal directioninto a tube with longitudinal ribs or feathers is produced,substantially as set forth.

3. In the art of rolling tubes, the process of rolling a hollow blank orbillet between two or more rolls, and a mandrel, which consists insubjecting a hollow blank or billet simultaneously to the action of twoor more positively-driven rolls, which impinge upon the blank before themain body of the caliber takes hold of the blank, and alongitudinallyactuated mandrel in connection with the squeezing actionexerted by the edges and the rims of the rolls, whereby the blank isstretched out to a tube with longitudinal fins, ribs or feathers.

4. The art of rolling a hollow blank or billet between two or more rollsand a mandrel,

which consists, in subjecting the blank to the action ofpositively-driven rolls and a longitudinally-actuated mandrelsimultaneously with the squeezing action of the caliber of the rolls,the distance between the edges of the grooves being of smaller size thanthe diameter of the blank or billet before it is rolled out, whereby arelatively large reduction of the blank is obtained and a tube isproduced with longitudinal ribs, fins or feathers, substantially as setforth.

5. The art of rolling a hollow blank or billet between rolls and amandrel, which consists, in subjecting the blank to the action of threeor more positively-driven rolls and a longitudinally-actuated mandrelsimultaneously with the squeezing. action of the edges of the rolls,whereby a relatively large reduction of the blank is obtained and a tubeis produced with longitudinal ribs, fins or feathers, substantially asset forth.

6. The art of rolling a hollow blank or billet between rolls and amandrel which consists in subjecting the blank to the action of three ormore positively-driven rolls and a longitudinally-actuated mandrel,simultaneously with the squeezing action of the edges of the rolls,whereby in one pass a reduction is obtained by which the rolled-out tubehas twice or more the length of the hollow billet before passing therolls, substantially as set forth. l

In testimony whereof I affix my signature in presence of two witnesses.

MAX MANNESMANN.

Witnesses:

ARCHER PET R, EMORY H. BOGLEY.

